Offering this very nice vintage Go/No Go gauge in very good used condition. It has a texture painted C-frame, much like a micrometer. It is marked in a ground identifacation area on the frame "SHEFFIELD CORP'N DAYTON O. U.S.A." and currently is set us for .500" to .506", but is adjustable via the removeable larger hardened block. In other words, the larger block can be replaced by another block you may wish to make or have made, giving this gauge a range from about 0" to .800 taking into consideration the radius in the throat currently. The two other gauge pads are adjustable as well, so the range of go/no go can be increase or decreased per your application. The benefit to the cast frame over solid machined gauges, is the increased stability of cast iron in this cast form during production, where temperature, and other conditions would otherwise effect the accuracy of a given solid steel gauge. This gauge is in very good shape, very little wear, no damage or rust, most of the textured paint is intact. A nice clean gauge overall!